From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: Memory-efficient way of opening large files in Emacs read-only Date: Thu, 08 Dec 2022 15:27:53 +0100 Message-ID: <87sfhqdl7a.fsf@mbork.pl> References: <8e91d0e8-2474-dd98-9bca-4606becd974d@mikpom.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="10737"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 29.0.50 Cc: help-gnu-emacs@gnu.org To: Mikhail Pomaznoy Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Dec 08 15:28:50 2022 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1p3HtJ-0002aj-Dp for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 08 Dec 2022 15:28:49 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p3Hsk-0007Qn-Uw; Thu, 08 Dec 2022 09:28:14 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p3Hsd-0007NX-Ui for help-gnu-emacs@gnu.org; Thu, 08 Dec 2022 09:28:13 -0500 Original-Received: from mail.mojserwer.eu ([195.110.48.8]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p3Hsb-00029R-Bn for help-gnu-emacs@gnu.org; Thu, 08 Dec 2022 09:28:07 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 3BB3B7E5C00; Thu, 8 Dec 2022 15:28:00 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rylWZ1kzPgm8; Thu, 8 Dec 2022 15:27:56 +0100 (CET) Original-Received: from localhost (178235147088.dynamic-3-poz-k-0-1-0.vectranet.pl [178.235.147.88]) by mail.mojserwer.eu (Postfix) with ESMTPSA id E3C447E8D05; Thu, 8 Dec 2022 15:27:55 +0100 (CET) In-reply-to: <8e91d0e8-2474-dd98-9bca-4606becd974d@mikpom.ru> Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:141458 Archived-At: On 2022-12-08, at 03:49, Mikhail Pomaznoy wrote: > Greetings! > > In my daily workflows I commonly stumble upon a task of peeking into > a header of a large (sometimes compressed) file. Those files can > commonly be gigabytes in compressed form so can't fit into > memory. I was wondering how can this be done in Emacs to leverage its > search and navigate capabilities? > > In a terminal this task is nicely accomplished with `less`, which > loads file on demand while you scroll (memory-efficiently) and > automatically detects at least gzip compression. However I am > struggling to do something similar in Emacs for quite a long time. > I tried VLF (requires manually switching chunks loaded, encountered > problems with compression), view-file (loads everything in memory), > running less in Emacs terminals (I prefer outside-Emacs terminals) but > for various reasons all this solutions are suboptimal and I usually > end up with using `less`. > > Is there something in Emacs I am missing? Is something like this makes > sense to develop (I consider to write something for Emacs) ? I am > using Emacs 28 and maybe in Emacs 29 there are novelties related to > this issue? I have no idea if Emacs has anything like this (I doubt), but the way I'd go about it would be to either leverage `less' inside one of the Emacs terminals or write some Elisp, colling to things like `gunzip' and `head' and then putting the result into some buffer. (I think you could even make it so that scrolling down would load the next portion in the background, =C3=A0 la modern Web. While I /hate/ this behavior of websites, here it could actually make sense.) Best, --=20 Marcin Borkowski http://mbork.pl